Vertical furnace with positive draft controller



Dec. 9, 1958 w. o. MORAN 2,363,442

VERTICAL FURNACE WITH POSITIVE DRAFT CONTROLLER Original Filed Nov. 5,1954 2 Sheets-Sheet 1 INVENTOR William 0.1101' an BY M/JM/ ATTORNEYSDec. 9, 1958 w. o. MORAN 2,863,442

VERTICAL FURNACE WITH POSITIVE DRAFT CONTROLLER Original Filed Nov. 5,1954 2 Sheets-Sheet 2 IN VENTOR mllidm aMora/n ATTORNEYS United StatesPatent VERTICAL FURNACE WITH POSITIVE DRAFT CONTROLLER William O. Moran,Tulsa, Okla.

Original application November 5, 1954, Serial No. 468,852, now PatentNo. 2,811,095, dated October 29, 1957. Divided and this applicationMarch 20, 1957, Serial No. 650,809

2 Claims. (Cl. 126-85) My invention is directed to a draft controller toassure a positive draft into a conduit or housing regardless of director relative wind conditions acting on the out--.

side of the draft controller. This application is a continuation-in-partapplication of my copending application Serial Number 313,568, filedOctober 7, 1952 now U. S. Patent 2,701,999, issued February 15, 1955,and a division of my copending application Serial No. 468,852, filedNovember 5, 1954, now U. S. Patent 2,811,095.

It is an object of my invention to provide a positive draft in a conduitor housing exposed to the outside atmosphere regardless of outsidedirect or relative wind conditions.

A still further object of my invention is to provide a positive draft toa chamber through a vertical conduit in communication therewith andthrough the same conduit introduce and pass exhaust gases leading fromthe chamber to provide a positive draft through the chamber.

A still further object of my invention is to provide a positive draft toa vertical furnace wherein the bottom end is closed off and air forcombustion flows downward while exhaust gases move upward through thevertical furnace.

Another object of my invention is to provide a vertically disposedfurnace having a tubular outer casing closed at the bottom, a tubularliner disposed within and in spaced relation with the outer casing andits bottom and forming an elongated annular combustion air supplypasburner assembly that pass up through said liner regardless of outsidewind conditions.

A still further object of my invention is to provide a positive draftcontrol for a furnace firebox wherein the furnace firebox has anenclosed housing in communication with its air induction opening andsaid housing has a reserve air induction chamber positioned below theinduction opening to afford combustion air for quick lighting of thefurnace and a housing head is in communication with said enclosedhousing, said housing head breaking up the air currents passing into thehousing head so that a uniform amount of air enters the furnace firebox.

Still further objects and the entire scope of applicability of thepresent invention will become apparent from the detailed descriptiongiven hereinafter; it should be understood, however, that the detaileddescription and specific examples are given by way of illustration onlyand, while indicating preferred embodiments of the invention, are notgiven by way of limitation, since various changes and modificationswithin the spirit and scope of 2 the invention will become apparent tothose skilled in the art from this detailed description.

For a more complete understanding of the nature and scope of myinvention, reference may be had to the following detailed descriptiontaken in connection with the accompanying drawing in which;

Fig. l is a perspective view of a housing head mounted on the end of anair intake housing which is shown broken off at its lower end;

Fig. 2 is a vertical cross sectional view of the housing and housinghead along line 22 of Fig. 3 but on a slightly different scale;

Fig. 3 is a horizontal cross sectional view of the housing head alongline 3-3 of Fig. 2; and

Fig. 4 is a partial vertical cross sectional view of a type of verticalfurnace which is closed at the bottom and is surmounted at its top by apositive draft head of the type shown in Fig. 1.

Throughout the description like reference numerals refer to similarparts.

In Figures 1, 2 and 3 there is shown an air intake housing head orpositive draft head 16 as mounted on the furnace shown in Fig. 4. Thishousing head is like that disclosed and claimed in my parentapplication, now U. S. Patent 2,811,095, issued October 29,, 1957, ofwhich this present application is a division. Air intake housing 15 inthe form shown is a cylindrical pipe and corresponds with the upper orvertically extending tubular casing 72 shown in Fig. 4. The air intakehousing head 16 mounted on the upper end of the air intake housing 15has a cylindrical thimble 17 at its base which is re ceived in the upperend of the air intake housing 15 and a bottom transverse plate 18attached to the upper end of thimble 17 and having an aperture 19therein permitting direct communication between thimble 17 and thehousing head proper to be described. The housing head proper ispolygonal in shape with four vertically extending sides 20, 20', 30 and30 attached to the outer edges of transverse bottom plate 18 andextending vertically therefrom and a transverse cover plate 22 attachedto the upper edges of the sides 20, 20, 30 and 30. In the form shownthere are seven vertically spaced horizontal rows of ten apertures each.The bottom row, for example, is shown with three spaced apertures 20a inside 20, three spaced apertures 20'a in side 20 oppositely positioned toapertures 20a, two spaced apertures 30a in side 30 and two oppositelypositioned apertures 3071 in side 30. The second horizontal row ofapertures from the bottom has two spaced apertures 20b in side 20, twooppositely spaced apertures 20'!) in side 20', three spaced apertures30b in side 30, and three oppositely spaced apertures 30b in side 30.The third, fifth and seventh rows from the bottom end are similarlyarranged to the bottom row while the fourth and sixth rows of aperturesfrom the bottom end are similarly arranged to the second row ofapertures described above.

The apertures are of uniform shape and size, and while shown as round,they may have other shapes. The total area of the apertures is such asto permit free flow of air through the head and the air inlet housingand chamber to which the head is attached.

In carrying out my invention the air flow against the outside of thehead 16 is broken up so that differently directed streams of air arecaused to flow in the head and on into the air intake housing connectedtherewith. This break up of the air into streams by the head is thoughtto take place as a result of providing the apertured and planar sideswhich in part make up the polygonal shaped elongated tubular head.

No matter what the force or direction. of the outside wind conditionsmay be that are acting on the air intake or positive draft control head16, there will be a uniform '3 HOW or air from the head to the airintake housing connected therewith and to the chamber to which the airintake housing is connected. The polygonal shaped head withits apertured:sides isthought to break up the air flow and induce a uniform-flow ofair from the head to the. chamber towhich it maybe connected to supplythe designed demands ofthe equipment in which the chamber is located andwith which the head is connected. With the polygonal shaped tubularbody. portion of the head a breakup of the air currents takes place tosupply the burner, for example, in the=furnace firebox. -At the sametime, any increase of windforce or direction acting outside on the-headwill not affect this-uniform flow of supply air from the head to thechamber to which. it is attached. It is thought that some of thebalancing effects of the wind pressure on the upwind side of the head,as explained more fully in 'my copendi ng application Serial No-313,568, filed October 7, 1952, now U. S. Patent 2,701,999, issuedFebruary 15, 1955, together with the vacuum created on the downwindside. of the head also occurs with this positive draftwcontrol'head.However, with the positive draft control head some'of the wind currentsare diverted by the head construction so that a positive draft issupplied to the air intake housing and the chamber to. which the headmay beaattached.

There is maintained within the draft controller or housing head 16 astill-day condition even though wind blows against the outside of theapertured'planarsides. Thus, the atmospheric pressure within the headand the conduits and compartments connected therewith is at normalatmospheric pressure. Bybeing able to maintain this normal atmosphericpressure condition'regar'dless of. outside wind conditions, a setcondition can bemaintained in the furnace firebox where the fire maybeadjusted or brought up to a maximum efficiencyas for a still-daycondition. Even though the fire is automatically turned on and off for amaximum and minimum demand, the still-day conditions are maintainedwhile outside conditions fluctuate.

In Fig. 4 furnace is generally indicated at 70'and is built with avertical tubular base portion 71 which is connected at its top withasmall vertically extending tubular casing 72 by the annular throat 73.The bottom end of the furnace is closed off by an integral transversebottom plate '74. concentrically within the'tubular .portion 71 is atubular liner generally indicated at75 which is supported in spacedrelation in a concentric-position from the tubular outer casing 71bytransverse apertured webs 76 and 77 toward the bottom and toprespectively. The bottom end of the liner 75 has an apertured bottomplate 78 through which the burners 79 extend that are fed by a fuel line80. The burner stems 79' extend through enlarged apertures 78 in plate78 and these enlarged apertures form passagesfor .combustion air to .theburners. The upper end ofliner-75 has mounted thereon a convergingcollar 75' through which exhaust gases from the burners 79 pass intothetubular casing 72 and out through a positive drafthead 16 mounted on thetop of casing 72.

Positive draft head 16 as shown in Fig. 4 is likethat as shown inFigures 1 and 2. Combustion air entersthrough this positive draft head16 and passes downwardly through the casing 72 and throughthe annularelongated passage generally indicated at 81 formed between theconcentric liner 75 within the casing 71. Furnace 70 has a reserve airchamber at 70' below the burner assembly.

In the operation of furnace 70, assuming that the wind is blowing fromthe left of the head 16 and striking its planar side, some air will passthrough the aligned apertures in the head from one side to the opposite,some air to support combustion in the furnace will enter through lowerapertures in the headytravel downward from within'head'.16,throughcasing 72 as indicated by the downwardly directed arrows, down throughthe annular chamber 81 outside of liner 75 and up through the reserveair chamber 70' at the bottom of the furnace and through apertures 73'to. the burners 7 9. The gases of combustion .from the burners'79 passupwardly in the combustion .chamber in liner 75, out through casing 72and to head 16 and out upper apertures of head 16 and particularly onthe downward side of the head.

While I have illustrated my positive draft head or air inlet head 16 asbeing used with a furnace it may equally as well be used wherever apositivedraft is required as in:pipe chambers carrying pipes giving errheat,

engine room stacks and other compartments that are to -beventilated.a'Withsthe positive draft. head, closedbot- .tom end .furnaces are .madeoperable since exchange of air for combustion and exhaust gases isenhancedthrough the same tubular casing.

I claim as 1 my. invention: 1. A vertically disposed furnace havingavertically extending tubular outer casing closed at thebottom, a

:positive draft to and exhausting exhaust gases from said furnace, saidpositive. draft controller having a plurality ofinterconnected.upwardlyextending'planar sides forming a casing. in communication with the topof said tubular stack, an imperforate end attached to and connecting the:upper ends of said planar sides, said planar .sides .having a pluralityof uniformly spaced apartrows of spaced apart apertures extendingtherethrough, said apertures in each of the rows being of uniformsizeand permitting free flow of airtherethroughto supply .airninimum tomaximum .air draft demand in said furnace equivalent to conditions of astill-day existing outside said ldraft controller regardless of outsidewindconditions acting onxsaid planar sides, each row ofapertures lyinginacommon plane'normal to said planar sides, some of said apertures in theplanar sides also furnishing' an exitpassage for said exhaust gases fromsaid furnace.

2.. A furnace of .the character described in claim 1 wherein the bottomof'said furnace has a reserve air'supply chamber for supplyingair tosaid burners.

=References Cited in the file of this patent UNITED STATES PATENTS636,044 .Humphreys Oct. 31, 1899 1,114,394 Siegler Oct...20, 19142,700,419 Gilmore Ian. 25, 1955 2,701,999 Moran Feb. 15, 1955 2,715,400Butler Aug. 16, 11955 2,764,972 Ryder Oct. 2, 1956

